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| 1 | 儿童肺功能系列指南(四):潮气呼吸肺功能显示文摘潮气呼吸流量-容积曲线(tidal breathing flow volume curve,TBFv)法检测婴幼儿肺功能在我国开展20年来,目前国内已有很多医院可进行此项检测,但一直缺乏相关的技术操作指南及检测报告解读指南或共识,供技术人员及临床医师参考使用。本指南主要就TBFV肺功能测定的原理、技术操作、注意事项、可获得的参数及其在不同疾病改变的特点与临床意义等进行阐述。 | | 2016 | 中华实用儿科临床杂志2016,31,21: | 75 |
| 2 | Combined detection of serum tumor markers for differential diagnosis of solid lesions located at the pancreatic head显示文摘BACKGROUND: The differential diagnosis of solid lesions located at the pancreatic head is very important for choosing therapies and setting up surgical tactics. This study was designed to evaluate the clinical significance of combined measurement of multiple serum tumor markers and the application of the receiver-operating characteristic (ROC) curves in the differential diagnosis of solid lesions located at the pancreatic head. METHODS: The serum levels of CA19-9, CA242, CA50 and carcinoembryonic antigen (CEA) in 112 patients with carcinoma of the pancreatic head and 38 patients with focal chronic pancreatitis in the pancreatic head were measured with ELISA. The sensitivity, specificity, positive likelihood ratio (PLR) and negative likelihood ratio (NLR) of the four serum tumor markers were calculated. The ROC curves for the four serum tumor markers were constructed and the area under the curve (AUC) was calculated. RESULTS: The AUCs of CA19-9, CA242, CA50 and CEA were 0.805, 0.749, 0.738 and 0.705; the PLRs were 1.91, 3.43, 5.09 and 5.46; and the NLRs were 0.41, 0.56, 0.59 and 0.71, respectively. Combined measurements increased the diagnostic specificity, and parallel combined testing increased the diagnostic sensitivity. CONCLUSIONS: Combined measurement of serum tumor markers CA19-9, CA242, CA50 and CEA is valuable in differential diagnosis of solid lesions located at the pancreatic head, and CA19-9 has the best diagnostic ability. Combined measurements can increase the specificity ofdiagnosis. Evaluation with the ROC curve is better than the sensitivity or specificity alone and the results are more integrated and objective. | Liao, Quan Zhao, Yu-Pei Yang, Ying-Chi Li, Li-Jun Long, Xiao Han, Shao-Mei | 2007 | Hepatobiliary & Pancreatic Diseases International2007,6,6: | 27 |
| 3 | Outcome and costs of laparoscopic pancreaticoduodenectomy during the initial learning curve vs laparotomy显示文摘AIM:To compare laparoscopic pancreaticoduodenectomy(TLPD) during the initial learning curve with open pancreaticoduodenectomy in terms of outcome and costs.METHODS:This is a retrospective review of the consecutive patients who underwent TLPD between December 2009 and April 2014 at our institution.The experiences of the initial 15 consecutive TLPD cases,considered as the initial learning curve of each surgeon,were compared with the same number of consecutive laparotomy cases with the same spectrum of diseases in terms of outcome and costs.Laparoscopic patients with conversion to open surgery were excluded.Preoperative demographic and comorbidity data were obtained.Postoperative data on intestinal movement,pain score,mortality,complications,and costs were obtained for analysis.Complications related to surgery included pneumonia, intra-abdominal abscess,postpancreatectomy hemorrhage,biliary leak,pancreatic fistula,delayed gastric emptying,and multiple organ dysfunction syndrome.The total costs consisted of cost of surgery,anesthesia,and admission examination.RESULTS:A total of 60 patients,including 30 consecutive laparoscopic cases and 30 consecutive open cases,were enrolled for review.Demographic and comorbidity characteristics of the two groups were similar.TLPD required a significantly longer operative time(513.17 ± 56.13 min vs 371.67 ± 85.53 min,P < 0.001).The TLPD group had significantly fewer mean numbers of days until bowel sounds returned(2.03 ± 0.55 d vs 3.83 ± 0.59 d,P < 0.001) and exhaustion(4.17 ± 0.75 d vs 5.37 ± 0.81 d,P < 0.001).The mean visual analogue score on postoperative day 4 was less in the TLPD group(3.5 ± 9.7 vs 4.47 ± 1.11,P < 0.05).No differences in surgery-related morbidities and mortality were observed between the two groups.Patients in the TLPD group recovered more quickly and required a shorter hospital stay after surgery(9.97 ± 3.74 d vs 11.87 ± 4.72 d,P < 0.05).A significant difference in the total cost was found between the two groups(TLPD 81317.43 ± 2027.60 RMB vs laparotomy 78433.23 ± 5788.12 RMB,P < 0.05).TLPD had a statistically higher cost for both surgery(24732.13 ± 929.28 RMB vs 19317.53 ± 795.94 RMB,P < 0.001)and anesthesia(6192.37 ± 272.77 RMB vs 5184.10 ± 146.93 RMB,P < 0.001),but a reduced cost for admission examination(50392.93 ± 1761.22 RMB vs 53931.60 ± 5556.94 RMB,P < 0.05).CONCLUSION:TLPD is safe when performed by experienced pancreatobiliary surgeons during the initial learning curve,but has a higher cost than open pancreaticoduodenectomy. | Chun-Lu Tan Hao Zhang Bing Peng Ke-Zhou Li | 2015 | World Journal of Gastroenterology2015,21,17: | 19 |
| 4 | Characteristics of paleoflood deposits archived in unit T0403 of Yuxi Site in the Three Gorges reservoir areas,China显示文摘Based on the detailed analyses,multi-proxies such as AMS 14 C dating,grain size,component and morphology of heavy minerals,micromorphology of zircon,magnetic susceptibility,Rb/Sr and Hg content are used to research the paleoflood sediments archived in the Yuxi Site.The research indicates that, since 7.6 kaBP,at least 16 times of paleoflood with water level above Wusong Elevation 147.024 m(a.s.l.) left deposits in the Neolithic layers of unit T0403 from the Yuxi Site.The results are induced from the following aspects:(1)The plaeoflood sediments take on great similarities with modern flood sediments in the Yuxi Site and Zhongba Site in probability cumulative curves which mainly show a pattern of 3 segments in fluvial pattern.(2)There is some resemblance between the heavy mineral components and the zircon shape characteristics of paleoflood deposits and those of modern flood deposits.(3) Magnetic susceptibility values(40.44―70.10SI)are lower than those of sediments from cultural layers (59.59―188.68SI).(4)Hg values(290.71―742.51 ng/g)are lower than those of sediments from cultural layers(344.16―10518.17 ng/g).(5)Rb/Sr values are higher than those of sediments from cultural layers, while those of the 4th,5th,6th,7th,8th cultural layers are high,which shows that they are inundated by paleoflood.The reason for many flood deposits existing is related to the site situated on the first terrace where the Yuxi River joins with the Yangtze River.As there are some similarities between the plaeoflood sediments and those of the Zhongba Site,it is feasible to confirm the existence of paleoflood sediments based on the above points. | ZHU Cheng MA ChunMei XU WeiFeng BAI JiuJiang ZHENG ChaoGui ZHU GuangYao WANG HuiLin CHEN Ye LU XueFeng | 2008 | Chinese Science Bulletin2008,53,S1: | 16 |
| 5 | Some new pre-warning criteria for creep slope failure显示文摘The forecasting of the failure time of a slope remains a worldwide problem because of many different possibilities of geological conditions in combination with many varying external factors such as climate and vegetation,and not well-defined or unknown time effects in deformation and failure models.The aim of this paper is to suggest a new method to carry out the phase division and to explore tangential angular features of the displacement-time curve of creep slopes as well as the acceleration characteristics in the process of slope deformation and the pre-warning criteria for critical failure.An imminent failure is pro-ceeded with usually three basic deformation phases,namely primary creep('decelerated') ,secondary creep('steadystate') and tertiary creep('accelerated') .Mostly,only during the accelerated phase the imminence of a possible slope failure is rec-ognized.The analysis of displacement data from a series of landslides allowed to recognize different evolutionary patterns of displacement.A quantitative approach was proposed to describe the tangential angle of the displacement-time curve and a new criterion based on the angle was put forward to divide the accelerated phase into three sub-phases:initial acceleration,medium acceleration,and the critical failure.A pre-warning criterion for critical failure is also proposed consequently. Changes of acceleration showed completely different characteristics from those of cumulative displacement and displacement in the process of slope deformation.The values of acceleration usually oscillate around 0 prior to the critical failure phase,whereas the acceleration increases abruptly when the deformation moves into the critical failure phase.This allows,therefore,for a method to forecast the time of the failure.So it is possible to define different alert acceleration threshold values to be used for emergency management. | HACK Robert | 2011 | Science China(Technological Sciences)2011,54,S1: | 15 |
| 6 | Investigation of gas content of organic-rich shale:A case study from Lower Permian shale in southern North China Basin,central China显示文摘Measuring gas content is an essential step in estimating the commerciality of gas reserves. In this study,eight shale core samples from the Mouye-1 well were measured using a homemade patented gas desorption apparatus to determine their gas contents. Due to the air contamination that is introduced into the desorption canister, a mathematical method was devised to correct the gas quantity and quality.Compared to the chemical compositions of desorbed gas, the chemical compositions of residual gas are somewhat different. In residual gas, carbon dioxide and nitrogen record a slight increase, and propane is first observed. This phenomenon may be related to the exposure time during the transportation of shale samples from the drilling site to the laboratory, as well as the differences in the mass, size and adsorptivity of different gas molecules. In addition to a series of conventional methods, including the USBM direct method and the Amoco Curve Fit(ACF) method, which were used here for lost gas content estimation, a Modified Curve Fit(MCF) method, based on the 'bidisperse' diffusion model, was established to estimate lost gas content. By fitting the ACF and MCF models to gas desorption data, we determined that the MCF method could reasonably describe the gas desorption data over the entire time period, whereas the ACF method failed. The failure of the ACF method to describe the gas desorption process may be related to its restrictive assumption of a single pore size within shale samples. In comparison to the indirect method, this study demonstrates that none of the three methods studied in this investigation(USBM, ACF and MCF) could individually estimate the lost gas contents of all shale samples and that the proportion of free gas relative to total gas has a significant effect on the estimation accuracy of the selected method. When the ratio of free gas to total gas is lower than 45%, the USBM method is the best for estimating the lost gas content, whereas when the ratio ranges from 45% to 75% or is more than 75%, the ACF and MCF methods, are the best options respectively. | Wei Dang Jin-Chuan Zhang Xuan Tang Xiao-Liang Wei Zhong-Ming Li Cheng-Hu Wang Qian Chen Chong Liu | 2018 | Geoscience Frontiers2018,9,2: | 14 |
| 7 | Reduced hemoglobin and increased C-reactive protein are associated with upper gastrointestinal bleeding显示文摘AIM: To investigate the early upper gastrointestinal endoscopy(endoscopy) significantly reduces mortality resulting from upper gastrointestinal(GI) bleeding. METHODS: Upper GI bleeding was defined as 1a, 1b, 2a, and 2b according to the Forrest classification. The hemoglobin(Hb), and C-reactive protein(CRP) were examined at around the day of endoscopy and 3 mo prior to endoscopy. The rate of change was calculated as follows:(the result of blood examination on the day of endoscopy- the results of blood examination 3 mo prior to endoscopy)/(results of blood examination 3 mo prior to endoscopy). Receiver operating characteristic curves were created to determine threshold values. RESULTS: Seventy-nine men and 77 women were enrolled. There were 17 patients with upper GI bleeding: 12 with a gastric ulcer, 3 with a duodenal ulcer, 1 with an acute gastric mucosal lesion, and 1 with gastric cancer. The area under the curve(AUC), threshold, sensitivity, and specificity of Hb around the day of endoscopy were 0.902, 11.7 g/dL, 94.1%, and 77.1%, respectively, while those of CRP were 0.722, 0.5 mg/dL, 70.5%, and 73%, respectively. The AUC, threshold, sensitivity, and specificity of the rate of change of Hb were 0.851,-21.3%, 76.4%, and 82.6%, respectively, while those of CRP were 0.901, 100%, 100%, and 82.5%, respectively. CONCLUSION: Predictors for upper GI bleeding were Hb < 11.7 g/dL, reduction rate in the Hb > 21.3% and an increase in the CRP > 100%, 3 mo before endoscopy. | Minoru Tomizawa Fuminobu Shinozaki Rumiko Hasegawa Akira Togawa Yoshinori Shirai Noboru Ichiki Yasufumi Motoyoshi Takao Sugiyama Shigenori Yamamoto Makoto Sueishi | 2014 | World Journal of Gastroenterology2014,20,5: | 13 |
| 8 | Study on the Relation between Garment Style and Ease Distribution显示文摘The shape of body and the ease of garment are the important elements in constructing garment style. However, the distribution of ease in garment is uneven and the curves showing different cross-sections of garment style with ease are unavailable in the literature. This information is crucial when the three-dimensional garment style is transformed into two-dimensional garment patterns. Thus, several different X-line style garments are produced by 3D draping technology, and the cubic spline is used to fit the cross sectional curves of BL, WL of body and garment. By comparing cross sections of body and garment, the ease at different location can be derived. Besides, garments in 10 different dimensions and quantities of style ease are included in the current study. By numerical operation on discrete ease data at different location, the fitted functions of ease distribution are obtained. | 王朝晖 张渭源 | 2004 | Journal of Donghua University(English Edition)2004,21,6: | 12 |
| 9 | Characteristics of distribution and transport of petroleum contaminants in fracture-karst water in Zibo Area, Shandong Province, China显示文摘Fracture-karst water is an important water resource for the water supply in North China. Petroleum contamination is one of the most problematic types of the groundwater pollution. The characteristics of distribution and transport of the petroleum contaminants in fracture-karst water are different from those in porous water. The flow velocity of fracture-karst water is much faster than the velocity of porous water on an average. Therefore, contaminant transport in fracture-karst water is an absolute advection-dominated problem. The plume of the petroleum contamination may extend to several kilometers from pollution sources. It was not caused by the oil pool floating on the water table but by the oil components dissolved and scattered in groundwater. The distribution of the petroleum contaminants over space are concentrated in the strong conductive zone on the plane. On the vertical section the highest concentration of the oil contaminants appeared in the strata where the contamination sources were | 朱学愚 刘建立 朱俊杰 陈余道 | 2000 | Science China Earth Sciences2000,43,2: | 12 |
| 10 | 流域土地利用变化对径流的影响显示文摘美国农业部开发的SCS水文模型可以定量反映土地利用/土地覆被变化对径流的影响,是应用较广的模型之一。在GIS支持下,以1965年西双版纳地形图及1988、2003年两期Landsat TM/ETM卫星影像获取的土地利用数据及实地土壤调查资料确定模型参数(CN值),通过分析CN值的变化来反映土地利用变化对径流的影响。研究结果表明,从1965~2003年,土地利用变化使流域径流系数增大,其中旱地、水田、有林地和草地的变化对流域径流的影响较大;人类活动逐渐向水文土壤条件较差的区域扩张,这种土地利用变化趋势使流域CN值增大,下垫面产流能力增强;人类活动干扰程度大的土地利用类型面积增加,这些土地利用方式对流域径流的影响越来越大。流域水田和水域面积减少,对流域径流的调节能力下降,势必影响到流域的水文循环。 | 郭宗锋 马友鑫 李红梅 刘文俊 | 2006 | 水土保持研究2006,13,5: | 11 |
| 11 | Learning curve of transumbilical suture-suspension single-incision laparoscopic cholecystectomy显示文摘AIM: To investigate the learning curve of transumbilical suture-suspension single-incision laparoscopic cholecystectomy (SILC). METHODS: The clinical data of 180 consecutive transumbilical suture-suspension SILCs performed by a team in our department during the period from August 2009 to March 2011 were retrospectively analyzed. Patients were divided into nine groups according to operation dates, and each group included 20 patients operated on consecutively in each time period. The surgical outcome was assessed by comparing operation time, blood loss during operation, and complications between groups in order to evaluate the improvement in technique.RESULTS: A total of 180 SILCs were successfully performed by five doctors. The average operation time was 53.58 ± 30.08 min (range: 20.00-160.00 min) and average blood loss was 12.70 ± 11.60 mL (range: 0.00-100.00 mL). None of the patients were converted to laparotomy or multi-port laparoscopic cholecystectomy. There were no major complications such as hemorrhage or biliary system injury during surgery. Eight postoperative complications occurred mainly in the first three groups (n = 6), and included ecchymosis around the umbilical incision (n = 7) which resolved without special treatment, and one case of delayed bile leakage in group 8, which was treated by ultrasound-guided puncture and drainage. There were no differences in intraoperative blood loss, postoperative complications and length of postoperative hospital stay among the groups. Bonferroni's test showed that the operation time in group 1 was significantly longer than that in the other groups (F = 7.257, P = 0.000). The majority of patients in each group were discharged within 2 d, with an average postoperative hospital stay of 1.9 ± 1.2 d. CONCLUSION: Following scientific principles and standard procedures, a team experienced in multi-port laparoscopic cholecystectomy can master the technique of SILC after 20 cases. | Ming-Xin Pan Zhi-Wei Liang Yuan Cheng Ze-Sheng Jiang Xiao-Ping Xu Kang-Hua Wang Hai-Yan Liu Yi Gao | 2013 | World Journal of Gastroenterology2013,19,29: | 11 |
| 12 | Approximate Degree Reduction of Bezier Curves显示文摘ApproximateDegreeReductionofBezierCurves*HuShimin(胡事民),SunJiaguang(孙家广),JinTongguang(金通光)+,WangGuozhao(汪国昭)+DepartmentofCompu... | 胡事民 孙家广 金通光 汪国昭 | 1998 | Tsinghua Science and Technology1998,3,2: | 10 |
| 13 | Aging Precipitation Behavior of 18Cr-16Mn-2Mo-1.1N High Nitrogen Austenitic Stainless Steel and Its Influences on Mechanical Properties显示文摘The solution-treated (ST) condition and aging precipitation behavior of 18Cr-16Mn-2Mo-1.1N high nitrogen austenitic stainless steel (HNS) were investigated by optical microscope (OM), scanning electron microscope (SEM), and transmission electron microscope (TEM). The results show that the ST condition of 18Cr-16Mn-2Mo-1.1N HNS with wN above 1% is identified as 1 100 ℃ for 90 min, followed by water quenching to make sure the secondary phases completely dissolve into austenitic matrix and prevent the grains coarsening too much. Initial time-temperature-precipitation (TTP) curve of aged 18Cr-16Mn-2Mo-1.1N HNS which starts with precipitation of 0.05% in volume fraction is defined and the 'nose' temperature of precipitation is found to be 850 ℃ with an incubation period of 1 min. Hexagonal intergranular and cellular Cr2N with a=0.478 nm and c=0.444 nm precipitates gradually increase in the isothermal aging treatment. The matrix nitrogen depletion due to the intergranular and a few cellular Cr2N precipitates induces the decay of Vickers hardness, and the increment of cellular Cr2N causes the increase in the values. Impact toughness presents a monotonic decrease and SEM morphologies show the leading brittle intergranular fracture. The ultimate tensile strength (UTS), yield strength (YS) and elongation (El) deteriorate obviously. Stress concentration occurs when the matrix dislocations pile up at the interfaces of precipitation and matrix, and the interfacial dislocations may become precursors to the misfit dislocations, which can form small cleavage facets and accelerate the formation of cracks. | LI Hua-bing, JIANG Zhou-hua, FENG Hao, MA Qi-feng, ZHAN Dong-ping (School of Materials and Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China) | 2012 | Journal of Iron and Steel Research(International)2012,19,8: | 10 |
| 14 | Application of isolation forest to extract multivariate anomalies from geochemical exploration data显示文摘Constructing a statistical model that best fits the background is a key step in geochemical anomaly identification. But the model is hard to be constructed in situations where the sample population has unknown and/or complex distribution. Isolation forest is an outlier detection approach that explicitly isolates anomaly samples rather than models the population distribution. It can extract multivariate anomalies from huge-sized high-dimensional data with unknown population distribution. For this reason,we tentatively applied the method to identify multivariate anomalies from the stream sediment survey data of the Lalingzaohuo district,an area with a complex geological setting,in Qinghai Province in China. The performance of the isolation forest algorithm in anomaly identification was compared with that of a continuous restricted Boltzmann machine. The results show that the isolation forest model performs superiorly to the continuous restricted Boltzmann machine in multivariate anomaly identification in terms of receiver operating characteristic curve,area under the curve,and data-processing efficiency. The anomalies identified by the isolation forest model occupy 19% of the study area and contain 82% of the known mineral deposits,whereas the anomalies identified by the continuous restricted Boltzmann machine occupy 35% of the study area and contain 88% of the known mineral deposits. It takes 4. 07 and 279. 36 seconds respectively handling the dataset using the two models. Therefore,isolation forest is a useful anomaly detection method that can quickly extract multivariate anomalies from geochemical exploration data. | WU Wei CHEN Yongliang | 2018 | Global Geology2018,21,1: | 9 |
| 15 | Characteristics and dynamics analysis of Populus euphratica populations in the middle reaches of Tarim River显示文摘Populus euphratica Oliv. is widely distributed along the Tarim River. Maintaining stability of P. euphratica population is important to local development. This study explored the static life table, survivorship curves and four function curves (survival rate, cumulative mortality rate, mortality density, and hazard rate), and development index of P. euphratica population in the middle reaches of Tarim River. The results indicated that the age structure of P. euphratica population belonged to positive pyramidal type, which meant young age-class individuals occupied most populations. The number ofⅠ-Ⅱage classes accounted for 66.2% of whole population, and this indicated that there were abundant subsequent seedlings resources to support the growth of P. euphratica population in the middle reaches of Tarim River. The survivorship curve of P. euphratica belonged to the Deevey Ⅲ (concave-type) and the development index was 47.72%. Four function curves revealed that the individuals of P. euphratica sharply decreased at the initial stage and then leveled off at the late stage of survival curve. Time sequence prediction models predicted that the number of midlife individuals would increase in future 10, 20, 30 years, and P. euphratica population grew steadily as a result of rich saplings. | Wu, JunXia Zhang, XiMing Deng, ChaoZhou Liu, GuoJun Li, Hong | 2010 | Journal of Arid Land2010,2,4: | 9 |
| 16 | Crustal structure and accurate hypocenter determination along the Longmenshan fault zone显示文摘Crustalstructureandaccuratehypocenterde┐terminationalongtheLongmenshanfaultzoneZHUZHAO1)(赵珠)JUNFAN1)(范军)SI-HUAZHENG2)(郑斯华)AK... | 赵珠 范军 郑斯华 长谷川昭 内茂木 | 1997 | Acta Seismologica Sinica(English Edition)1997,10,6: | 9 |
| 17 | Load curve smoothing strategy based on unified state model of different demand side resources显示文摘Renewable energy based distributed generation(DG) has the potential to reach high penetration levels in the residential region. However, its integration at the demand side will cause rapid power fluctuations of the tieline in the residential region. The traditional generators are generally difficult to manage rapid power fluctuations due to their insufficient efficiency requirements and low responding speed. With an effective control strategy, the demand side resources(DSRs) including DGs, electric vehicles and thermostatically-controlled loads at thedemand side, are able to serve as the energy storage system to smooth the load fluctuations. However, it is a challenge to properly model different types of DSRs. To solve this problem, a unified state model is first developed to describe the characteristics of different DSRs. Then a load curve smoothing strategy is proposed to offset the load fluctuations of the tie-line of the residential region, where a control matrix deduced from the unified state model is introduced to manage the power outputs of different DSRs,considering the response order and the comfort levels.Finally, a residential region with households is used to validate the load curve smoothing strategy based on the unified state model, and the results show that the power fluctuation rate of the tie-line is significantly decreased.Meanwhile, comparative study results are shown to demonstrate the advantages of the unified state model based load curve smoothing strategy. | Mingshen WANG Yunfei MU Tao JIANG Hongjie JIA Xue LI Kai HOU Tong WANG | 2018 | Journal of Modern Power Systems and Clean Energy2018,6,3: | 8 |
| 18 | Dynamic subsidence prediction of ground surface above salt cavern gas storage considering the creep of rock salt显示文摘A new model is proposed to predict the dynamic subsidence of ground surface above salt cavern gas storage during the leaching and storage, which takes into account the creep of rock salt. In the model, the extended form of Gaussian curve is adopted to figure out the shape of subsidence areas. The corresponding theoretical formulas are derived. In addition, parameters are studied to investigate the surface subsidence as a function of the salt ejection rate, internal pressure, buried depth, diameter, height, running time, etc. Through an example, the subsidence of the salt cavern gas storage located at Jiangsu of China obtained by the new model was compared with those by Peter A F formula, Schober & Sroka formula and FLAC3D through simulation. The results showed the proposed model is precise and correct, and can meet the actual engineering demands. The surface subsidence is equidirectional with the increase of salt ejection rate, depth, diameter, height, and running time, but reverse to the increase of internal pressure. The depth, diameter, running time and internal pressure have great effects on the subsidence, whereas the salt ejection rate and height have little influences on it. | WANG TongTao1, YAN XiangZhen1, YANG XiuJuan1 & YANG HengLin2 1 College of Pipeline and Civil Engineering, China University of Petroleum, Qingdao 266555, China 2 CNPC Drilling Research Institute, Beijing 100097, China | 2010 | Science China(Technological Sciences)2010,53,12: | 8 |
| 19 | Modeling and prediction of children’s growth data via functional principal component analysis显示文摘We use the functional principal component analysis(FPCA) to model and predict the weight growth in children.In particular,we examine how the approach can help discern growth patterns of underweight children relative to their normal counterparts,and whether a commonly used transformation to normality plays any constructive roles in a predictive model based on the FPCA.Our work supplements the conditional growth charts developed by Wei and He(2006) by constructing a predictive growth model based on a small number of principal components scores on individual's past. | HU Yu HE XuMing TAO Jian SHI NingZhong | 2009 | Science China Mathematics2009,52,6: | 8 |
| 20 | Effects of Nb on the microstructure and mechanical properties of 38MnB5 steel显示文摘The effects of the microalloying element niobium(Nb) on the microstructure and mechanical properties of the hot stamped steel 38 Mn B5 were investigated. The impact of Nb addition on the microstructure was studied through scanning electron microscopy(SEM), transmission electron microscopy(TEM), and X-ray diffraction(XRD). The experimental results indicated that the microstructures of the steel containing Nb were finer than those of the steel without Nb. Moreover, Nb mainly presented as a second-phase particle in 38MnB5 steel, and the particles included Nb carbonitrides. In addition, the tensile strength and elongation of the hot rolled and hot stamped steels were also measured, and they demonstrated that the appropriate addition of Nb was beneficial to the mechanical properties of 38 MnB5. Under the same conditions, the tensile strength of 38 MnB5 Nb was higher than that of 38 MnB5, which increased from 2011 to 2179 MPa. The yield strength also increased from 1316 to 1476 MPa, and the elongation increased from 5.92% to 6.64%. Overall, Nb had a positive effect on the performance of the hot stamped steel. | Li Lin Bao-shun Li Guo-ming Zhu Yong-lin Kang Ren-dong Liu | 2018 | International Journal of Minerals,Metallurgy and Materials2018,25,10: | 8 |